Ignition device.



I. I". GAVANAGH. IGNITION DEVIGE.

-APPLI(7ATION FILED AUG. 3, 1911.

1,011,884. Patented Dec. 12,1911

Fig. 1. Fig. 2. 22 a) ,2/ 2.1 A9 KY '23 0 Wfi'ffi 5: I 55 II a c Minesacs:

UNITED STATES PATENT OFFICE.

JOHN F. CAVANAGH, 0F PROVIDENCE, RHODE ISLAND, ASSIGNOR OF THREE-FOURTHST0 LINDSLEY AND ALLEN ELECTRIC COMPANY, OF PROVIDENCE, RHODE ISLAND, A

CORPORATION OF RHODE ISLAND.

' IGNITION DEVICE.

tion Devices, of which the following is a specification, reference beinghad therein to the accompanying drawing. This invention relates to anignition device especially adapted to befmounted directly upon the sparkplug of a hydrocarbon engine, and the object of the invention is toprovide an extremely small and compact yet highly efficient devicecomprising a coil' carrying casing having a" central recess whereby itmay be readily mounted upon a spark plug and a coil having a hollowcenter 7 portion mounted in said casing and surrounding said receivingrecess, said casing being also provided with simple and effective meanswhereby the device'may be detzichably connected to the ordinary sparkfurther object of the invention is that by mounting this device directlyupon the spark plug it serves as an insulating hood or cap to; inclose,cover and protect the otherwise exposed conducting parts of the Thenagain, it eliminates all spark plug. high tension wiring therebyobviating the necessity of heavy insul'ationagainstmoisture or otherexternal influences.

With these and other objects in View, the invention consists of certainnovel features of construction, as will be-more fully' described andparticularly pointed out in the appended claims. v

Of the accompanyin drawings: Figure 1is a sectional view 0 the casingand coil showing the same applied to a spark plug of "standardconstruction. .Figl 2'is a modified construction of casingshowing thesame as being adapted to be filled from the bottom instead of from thetop as that illustrated in Fig. 1. Fig. 3-shows the upper portion of aspark plug with the'spring wire contact connected thereto. Fig. 4-is asectional plan view of the-clamp for attaching the device to the sparkplug. Fig. 5is a wiring diagram of my improved ignition device.

Iteferring to the drawings, 10 designates a cylindrical casing formedpreferably by the molding of insulating material, the same Specificationof Letters Patent. Application filed August a, 1911.

Patented Dec. 12, 191 1.

Serial No. 642,208.

' being provided with a bottom portion 11 and a central tubular member12 forming a central longitudinally disposed recess 20 for the receptionof the upper end 13 of the ordinary spark plug 14;, an outer annularchamber 27 being formed around the inner central recess for thereception of the coil.

hereinafter described. A contact member 15 ismolded or otherwise securedinto the base portion of the casing to which the lead wire, not shown,may be connected. Into this base portion is also molded or otherwisefixed a metal clamping member 16 which is preferably made to conform tothe nut portion of the standard spark plug and is split as at 17 andprovided with a binding screw 18 for the purpose of being set up-firrnlyto secure the casing rigidly onto the spark plug of an engine. A cap 19,alsdof insulating material, maybe threaded or otherwise socured into the;upper end of the casing. A contact plate 21 is preferably secured tothe inner side of said cap and projects out therefrom into the upper endof the coil chamber.

In this device I preferably use a high frequency coil, that is, a coilwhich depends for its excitation upon the oscillatory dis charge of acondenser. This coil consists of an outer primary and inner secondarywinding and is particularly well adapted for my present purpose as it isprovided with a hollow middle portion and is adapted to be inserted intothe annular chamber 27 and about the spark. plug receiving recess 20.Oneend of the secondary winding 23 of this coil may-be connected at itsupper end to the contactplate 21' by the wire 22, the other end of saidcoil-being grounded on the engine through the wire 24, clamp 16 andspark plug and when the coil is placed in position over the spark plugthis contact spring engagesv the plate 21 thereby completing the circuitthrough the plug.

In the modified form of easing illustrated in Fig. 2 the same is alsomade in a cylindrical form, the top portion being provided with a fixedhead or cap 28 thereover into which is molded or otherwise fixed thecontact member 15. After the coil 29 has been placed in the coil chamber27 from the bottom end of the casing, a head'30 having a inductance 36thence through wire 37 to one applied to a four cylinder engine inwhich.

34 designates the source of energy of comparatively low voltage which iscomlected to one wire 35 which passes through the point 38 of theinterrupter through to the other interrupter point- 39 and wire 40 backto the source of energy. In other words, the inductance and interrupterare in scries. The terminal 38 of the interrupter is ber 44 which isinsulated at 44.

connected to ground through the. wire 45. One terminal 41 of thecondenser 42 is con nected to the point 39 of the interrupter. The otherterminal 43 of said condenser is connected to the rotating distributingmem- The distributer contact points 46,. 47, 48 and 49 are adapted toreceive the current from the rotating distributing arm 50 to conduct thesame to their respective ignition devices 51 and through its spark plugs14 to ground, in other words, the condenser connected in series with theprimary winding of the respective ignition devicesacross the contactpoints of the interrupter. It will be understood from the above that thecondenser discharges through the primary winding of the high frequencycoil, mounted upon the spark plug. I In the operation of this device thecon tact members 38 and .39 are closed by the mechanical action of arotating cam illustrated and described in my copending applicationSerial No. 625,075. Immediatel upon the completion of the circuit througsaid interrupter the points 38 and 39 are instantly separated by themechanism described in said co-pending application. The inductance coil36 charges the condenser 42 which instantly discharges through thedistributer and the proper coil. This discharge through the primarywinding of said coil induces the high. frequency spark in the gap 52 inthe spark plug 14 serving to ignite the mixture in the englne.

I claim:

1. In an ignition device, a coil provided witha hollow center portionfor the reception of a spark plug, and a contact to complete the circuitthrough said spark plug when the device is applied thereto.

2. In an ignition device, acoil provided with a hollow center portionfor the reception of a spark. plug, a contact to complete the circuitthrough said spark plug when the device is applied thereto and aninsulating casing inc-losing said coil.

3. In an ignition device a coil carrying casing rovided with a centrallongitudinal recess or the reception of 'a spark plug, a coil providedwith a hollow center portion mounted in said casing and surrounding saidspark plug receiving recess and a contact in said recess to complete thecircuit through the spark plug when the device is applied thereto.

4. In an ignition device a coil provided with a hollow center portionfor the reception of a spark plug, and "a contact to com' plete thecircuit through said spark plug when the device is applied thereto, andmeans for securing said device in position.

5. In an ignition device, a coil provided with a hollow center portionfor the reception of a spark plug, and a contact to complete the circuitthrou b said spark plug when the device isapp ied thereto and aninsulating casing inclosing said coil'and means for removably securingsaid casing to its spark plug.

In testimony whereof I afiix my signature in presence of two witnesses.

JOHN F. CAVANAGH.

